So first off: Domain Turns of about one month. Terminology changes somewhat from game to game, but pretty much everyone agrees that this is about the length of time for domain. I also agree. Moving on.
Where I differ is the idea that Domains should take just one or two "domain actions" each Domain Turn, because that inevitably ends up with a crap tonne of things that are defined as "free actions" or "not an action" or whatever because obviously domains need to be able to conduct diplomacy and move troops and continue work on their castle and shit at the same time. Because well, obviously. Which brings us to the Council.
The Council
The default assumption is that every Domain is actually run by the Council. There may or may not be a titular ruler, but the people tasked with actually giving out orders are the people who actually matter. This allows it to be played as an RPG, because of course the player characters are presumably going to be four to six characters who are co-equal ensemble protagonists.
Each member of the council can take their own Domain actions, and the only restriction is that all Domain actions have costs, and you have to actually pay for all the ones you want to take. The actual members of the council vary from Domain to Domain. That is, there are a bunch of hats that you could wear, and everyone in the council gets to pick exactly one. Each one gives you slightly different super powers, with the idea that characters of any particular class would have more than one council position that would seem like a decent fit such that if you have two Paladins one can be the General and the other can be the Champion and they aren't directly pissing in each other's cereal. Similarly, one Rogue could be the Chancellor and another Rogue could be the Spymaster.
- Admiral; Adviser; Aerie Keeper; Alchemist; Ambassador; Archon; Astrologer; Beastmaster; Calender Keeper; Chamberlain; Champion; Chancellor; Chaplain; Consul; Dean; Diviner; Dungeon Keeper; Engineer; Executioner; Forgemaster; General; Guildmaster; Harbormaster; Herald; Historian; Huntmaster; Inquisitor; Jester; Judge; Magician; Marshal; Master Gardener; Minister of Agriculture; Minister of Works; Necromancer; Physician; Poet; Priest; Puppeteer; Ritualist; Scribe; Sheriff; Spymaster; Stablemaster; Steward; Treasurer
Structurally, having about fifty council positions should take up around 3 pages. The council positions don't need to be that long, because they only have a small collection of additive abilities. Any council member could shill out to start building a fortress, but the Court Engineer is better at it.
At the highest level, the various divine and fiendish realms can be their own Domains with their own councils. Orcus is simply the "Court Necromancer" of the Demon Princes.
-Username17